Java FileDescriptor Example with FileInputStream and FileOutputStream
July 16, 2014
java.io.FileDescriptor has been introduced in JDK 1.0. FileDescriptor represents an open file, socket. FileDescriptor is used with FileInputStream and FileOutputStream. Two instances of FileOutputStream or FileInputStream can communicate using FileDescriptor. In this page I will show two example which will use FileDescriptor, one with FileOutputStream and second with FileInputStream.
FileDescriptorDemoOne.java
package com.cp.io;
import java.io.File;
import java.io.FileDescriptor;
import java.io.FileOutputStream;
import java.io.IOException;
public class FileDescriptorDemoOne {
public static void main(String[] args) throws IOException {
File file = new File("D:/test.txt");
FileOutputStream fos1 = new FileOutputStream(file);
FileDescriptor fd = fos1.getFD();
//passing FileDescriptor to another FileOutputStream
FileOutputStream fos2 = new FileOutputStream(fd);
fos2.write("Hello World!".getBytes());
fos1.close();
fos2.close();
}
}
Now find the example of FileDescriptor with FileInputStream.
FileDescriptorDemoTwo.java
package com.cp.io;
import java.io.File;
import java.io.FileDescriptor;
import java.io.FileInputStream;
import java.io.IOException;
public class FileDescriptorDemoTwo {
public static void main(String[] a) throws IOException {
File file = new File("D:/test.txt");
FileInputStream fis1 = new FileInputStream(file);
FileDescriptor fd = fis1.getFD();
//passing FileDescriptor to another FileInputStream
FileInputStream fis2 = new FileInputStream(fd);
int i=0;
while((i=fis2.read())!=-1){
System.out.print((char)i);
}
fis1.close();
fis2.close();
}
}
